The United Kingdom is made up of England, Scotland, Wales and Northern Ireland. Its official name is "United Kingdom of Great Britain and Northern Ireland". It has one government based in London and has one currency: the pound stirling (£).
Great Britain is an island which is made up of three countries: England, Scotland and Wales. Great Britain is the political term which describes the political union of the kingdoms of England, Wales and Scotland. Northern Ireland is not part of Great Britain.
England is one of the four countries that make up the UK and one of the three that makes up Great Britain. England is the largest country in the UK. London is the capital of England.
Scotland shares a border with England, but it is not in England. Its capital city is Edinburgh.
Wales is in the west of Great Britain and the capital city is Cardiff.
Northern Ireland is part of the UK, but it is not in Great Britain. Northern Ireland can be found in Ireland, which is the island to the west of Great Britain. The capital is Belfast.
The Republic of Ireland, in the south, is an independent country with its own laws, government and currency (€).
What is the capital city of the UK? It is London, of course.